Valentine, Willard L.
Holt, Rinehart and Winston, 1949
Buku Teks
Christensen, Larry B., 1941-, author
Pearson/Allyn & Bacon, 2007
Buku Teks
Christensen, Larry B., 1941-, author
Allyn and Bacon, 1988
Buku Teks
Herve Abdi, author
Oxford University Press, 2009
Buku Teks
Dong, Tiansi, author
[Springer, ], 2012
eBooks